These insulated cables gently warm the soil for faster germination and better growth. Equipped with a built-in thermostat designed to maintain temperatures between 77 degrees Fahrenheit and 85 degrees Fahrenheit. The water-resistant cables are available in three lengths: 12 feet, 24 feet and 48 feet.They’re flexible to adapt to most any growing space and are suitable for use indoors or out. Instructions are included. 36W / 120V / 0.33A.